The lymphatic system is organized like the blood system in that it includes a system of numerous tiny vessels connected to a network of larger vessels, and through which system and network a liquid medium containing solutes and particulates is transferred. A healthy lymphatic system continuously drains lymphatic fluid, consisting of a mixture of lymph, water, proteins and other matter, away from various interstitial areas of the body and back into the blood system. Lymph is the clear, liquid medium or solvent of the lymphatic system.
The lymph fluid is pumped through the lymphatic system and away from various body areas by both the action of adjacent muscle tissue and the contraction of the larger lymphatic vessels. Foreign matter is filtered out of the lymph fluid as the fluid passes through bundles of lymph nodes during its course through the lymphatic system. The lymph nodes also monitor the contents of the lymph fluid to determine if any appropriate immune reactions should be initiated by the host's immune system. The lymph is then transferred back into the blood system after this filtration.
Lymphedema is a deficiency, blocking or dysfunction of the lymphatic system that limits the flow of lymph fluid from a body area. The most frequent causes of lymphedema include primary insufficiency, traumatic accidents, chronic venous diseases, radiation therapy of the lymph nodes, prostate operations, mastectomies, amputations and other surgical operations. Lymphedema most typically occurs in arms and legs, but most other body areas can become lymphedemic, such as the genitals and the trunk of the body.
Lymphedema and edema can cause reduction in mobility, pain, embarrassment and serious emotional depression. Rapid swelling, such as caused by radiation therapy or a surgical operation, can be especially painful as the body tissue is effectively being torn apart by the fluid pressure. The World Health Organization recently estimated that approximately 500 million people currently suffer from some form of lymphedema.
Individual cases of lymphedema are typically diagnosed as belonging to either a primary or a secondary class. Primary lymphedema is a condition where the lymphatic system is chronically or acutely overwhelmed by the volume of lymphatic fluid to be evacuated. Chronic primary lymphedema is often a genetically determined condition. Acute primary lymphedema, and edema, can be caused by an injury or trauma where the lymph system is properly functioning but is temporarily overwhelmed. Swelling and/or edema caused by burns, sprains and other injuries are typically alleviated after a few days or weeks in a patient in generally good health. However, even temporary swelling can be painful to the patient and can result in fibrosis.
Secondary lymphedema is typically presents as a relatively sudden cessation or deep reduction of the functionality of a portion of the lymphatic system. The most frequently occurring causes of secondary lymphedema include radiation therapy, mastectomies, amputations and other surgical operations.
Regardless of cause or class, a significant limitation or attenuation of the necessary progress of lymphatic fluid through the lymphatic system may result in a concentration or swelling of the protein bearing lymph fluid in the interstitial area of the soft tissue of an affected limb or body region. Chronic lymphedema more often results in severe and even life threatening consequences than acute edemas.
Any sustained accumulation of proteins delivered to the body tissue by the blood capillaries, and not removed by the lymphatic system, will cause a swelling of fluid in the interstitial areas of the body tissues. The oxygenation of adjacent tissue is thereby reduced and the healing process is retarded. A localized accumulation of proteins further compounds this situation by directly stimulating chronic inflammation. Chronic inflammation usually results in the formation and dilation of additional capillaries. These additional blood vessels deliver undesirable excess heat to the swollen area. This inopportune heating of the protein rich interstitial fluid increases the incidence and virulence of opportunistic bacteriological infections.
Conventional treatment techniques for lymphedema include the use of benzo-pyrene drugs, massage therapy, physical exercise, compression bandages and compression garments. Treatment strategies that apply physical pressure to a swollen, edemic or lymphedemic body area can be divided into those which provide intermittent forced compression and those which maintain a relatively constant pressure over time. Looking first at intermittent forced compression devices, Ferrari, in U.S. Pat. No. 5,025,781, discloses an inflatable cuff that is alternately inflated and deflated to deliver a uniform blanket compression against the circumference of a swollen limb. This action may, however, exacerbate the patient's condition by collapsing blood vessels, increasing leakage into the interstitial areas and obstructing lymphatic outflow.
Bertinin, in U.S. Pat. No. 5,245,990, describes an inflatable sheath which consists of a number of inflatable tubes. The tubes are inflated and deflated in a sequence starting from the most distal and ending at the most proximal. Inventor Bertinin intends to supply a wave-like massage to the swollen limb. Bertinin's method of timed and sequential inflation and deflation is similar to the invention of Ferrari in that a uniform blanket pressure is exerted against the swollen tissue at any particular moment. This blanket pressure is reported to typically be ineffective by medical practitioners of the art. In addition, compressive devices which include pneumatic pumps can cause damage to the health of the patient and must typically by applied by a trained medical practitioner.
Schneider packs, an alternative prior art example, are used to apply constant pressure to a body part Schneider packs consist of small packs of randomly placed pieces of high density foam bound within a tubular cloth pouch or tube. Schneider packs are incorporated into bandaging and usually can not be attached by the patient without assistance.
Improvements in treating lymphedema were recently made by Tony Reid, M.D. and Applicant in a previous invention. This previous invention of Reid and Applicant, and marketed as a Reid Sleeve, includes a sheet of convoluted plastic foam and a means to push the extending elements, or fingers, of the convoluted foam sheet against a swollen body part. The foam fingers are prearranged neatly on the foam sheet in well ordered rows and columns, and create a grid pattern of high and low pressure areas when pressed against the patient's body area. The convoluted foam sheet is encased in an inner lining of a spandex material and an outer lining of relatively heavy nylon fabric. Adjustable velcro straps and matching D ring straps are sewn into the outer lining, by which means the convoluted plastic foam sheet is secured and pressed against and/or around a body part. In application, a medical practitioner can use a pressure gauge while applying this earlier invention of Reid and Applicant to cinch the velcro straps to a particular pressure point or to within a preferred pressure range.
The use of a solid convoluted foam sheet adds, in light of the present invention, unnecessarily to the weight of the device of Reid and Applicant. Furthermore, the use of a heavy nylon fabric in the outer lining of the device of Reid and Applicant limits the patient's range of motion and wearing comfort. A typical Reid Sleeve arm design weighs over three pounds. In addition, the direct attachment of the velcro strapping and matching D ring straps to the heavy nylon fabric reduce the uniformity of pressure exerted by individual fingers across the total circumference of a limb or body part.
The design of the invention of Reid and Applicant is not configurable to apply pressure to a combination of a limb and an adjacent body area (e.g. leg and groin, leg and hip, arm and shoulder, and etc.) with a single assembly device. The employment in the Reid Sleeve of heavy nylon fabric also limits the adjustability of a particular sleeve to a small range of arm circumferences or arm sizes.
There has been a long felt need in the medical treatment of lymphedema, edema and other soft tissue swelling for a more effective, widely applicable, comfortable, easily transportable, and more patient manageable device and method of use.